Sarcomas are cancers that arise in the "connective tissue" of the body. The most common sites are muscle and bone. Soft tissue sarcomas usually occur in muscle, but can appear anywhere. Most can be treated with brachytherapy if accessible enough and in a location where the implant can be relatively immobilized. For example, sarcomas near the heart would not be treatable due to the heart motion.
With the patient under general anesthesia, the surgeon removes the visible tumor. The brachytherapy physician then places the catheters that will contain the radioactive source, where the tumor was and also includes a "margin" to ensure that any microscopic spread will also be irradiated. The wound is closed, leaving the ends of the catheters to protrude through the skin. The area is anointed with antibacterial ointment and bandaged. When the physician deems the patient's wounds sufficiently healed, the imaging procedure, using either CT or radiography is done. These special x-ray films are necessary for the computerized treatment planning and radiation dose calculations. After the treatment plan has been approved by the physician, the ends of the protruding catheters are connected to "transfer tubes" which are connected to the afterloader which houses the radioactive source. The afterloader directs the source through each of the catheters to deliver the precise amount of radiation. The implant is usually treated 8 to 10 times, twice a day, then removed.